HEMA LEC - Hemolytic Anemias due to Intrinsic defects

Question 1

a. Characterized by a sudden loss of blood resulting from trauma or other severe forms of injury

Answer 1

Acute blood loss anemia

Question 2

b. Clinical symptoms: Hypovolemia, rapid pulse, low blood pressure, pallor

Answer 2

Acute blood loss anemia

Question 3

. Laboratory: Normocytic/normochromic anemia; initially normal reticulocyte count, hemoglobin/ haematocrit; in a few hours, increase in platelet count and leukocytosis with a left shift, drop in hemoglobin/hematocrit and RBC; reticulocytosis in 3-5 days

Answer 3

Acute blood loss anemia

Question 4

a. Characterized by a gradual, long-term loss of blood; often caused by gastrointestinal bleeding

Answer 4

Chronic blood loss anemia

Question 5

b. Laboratory: Initially normocytic/ normochromic anemia that overtime causes a decrease in hemoglobin/ haematocrit; gradual loss of iron causes microcytic/hypochromic anemia

Answer 5

Chronic blood loss anemia

Question 6

All cause a normocytic/normochromic anemia usually hereditary with reticulocytosis due to accelerated destruction.

Answer 6

hemolytic anemias due to intrinsic defects

Question 7

Most common membrane defect; autosomal dominant; characterized by splenomegaly, variable degree of anemia, spherocytes on the peripheral blood smear.

Answer 7

hereditary spherocytosis

Question 8

b. Increased permeability of the membrane to sodium.

Answer 8

hereditary spherocytosis

Question 9

c. Results in loss of membrane fragments; erythrocytes have DECREASED SURFACE-TO-VOLUME RATIO; rigid spherocytes culled/ removed by splenic macrophages.

Answer 9

hereditary spherocytosis

Question 10

d. Laboratory: Spherocytes, MCHC may be > 37g/dL, increased OSMOTIC FRAGILITY AND INCREASED SERUM BILIRUBIN

Answer 10

hereditary spherocytosis

Question 11

a. Autosomal dominant; most persons asymptomatic due to normal erythrocyte life span; > 25% ovalocytes on the peripheral blood smear

Answer 11

Hereditary elliptocytosis (ovalocytosis)

Question 12

b. Membrane defect is caused by polarization of cholesterol at the ends of the cell rather than around pallor area.

Answer 12

Hereditary elliptocytosis (ovalocytosis)

Question 13

a. Autosomal dominant; variable degree of anemia; up to 50% stomatocytes on the blood smear.

Answer 13

Hereditary stomatocytosis

Question 14

b. Membrane defect due to abnormal permeability to both sodium and potassium; causes erythrocyte swelling

Answer 14

Hereditary stomatocytosis

Question 15

a. Autosomal recessive; mild anemia associated with steatorrhea, neurological and retinal abnormalities; 50-100% of erythrocytes are acanthocytes.

Answer 15

Hereditary acanthocytosis (abetalipoproteinemia)

Question 16

b. Increased cholesterol: lecithin ratio in the membrane due to abnormal plasma lipid concentrations; absence of serum B-lipoprotein needed for lipid transport.

Answer 16

Hereditary acanthocytosis (abetalipoproteinemia)

Question 17

a. Sex-linked enzyme defect; most common enzyme deficiency in the hexose monophosphate shunt
d. Usually, not anemic until oxidatively challenged (primaquine, sulfa drugs); then severe haemolytic anemia with reticulocytosis.

Answer 17

G6PD (glucose-6-phosphate dehydrogenase) deficiency

Question 18

c. Results in oxidation of hemoglobin to methemeglobin (Fe3+); denatures to from Heinz bodies.

Answer 18

G6PD (glucose-6-phosphate dehydrogenase) deficiency

Question 19

b. Reduced glutathione levels are not maintained because of decreased NADPH generation.

Answer 19

G6PD (glucose-6-phosphate dehydrogenase) deficiency

Question 20

a. Autosomal recessive; most common enzyme deficiency in Embden-Meyerhof pathway

Answer 20

Pyruvate kinase (PK) deficiency

Question 21

b. Lack of ATP causes impairment of the cation pump that controls intracellular sodium and potassium levels.

Answer 21

Pyruvate kinase (PK) deficiency

Question 22

c. Decreased erythrocyte deformability reduces their life span.

Answer 22

Pyruvate kinase (PK) deficiency

Question 23

d. Severe haemolytic anemia with reticulocytosis and echinocytes.

Answer 23

Pyruvate kinase (PK) deficiency

Question 24

a. An acquired membrane defect in which the red cell membrane has an increased sensitivity for complement binding as compared to normal erythrocytes
b. Etiology unknown

Answer 24

Paroxysmal nocturnal hemoglobinuria (PNH)

Question 25

c. All cells are abnormally sensitive to lysis by complement.

Answer 25

Paroxysmal nocturnal hemoglobinuria (PNH)

Question 26

e. Although Ham’s and sugar water tests have been traditionally used in diagnosis of PNH, the standard now used is flow cytometry to detect deficiencies for surface expression of glycosyl phosphatidylinositol (GPI) – linked proteins such as CD55 and CD59.

Answer 26

Paroxysmal nocturnal hemoglobinuria (PNH)

Question 27

d. Characterized by: Pancytopenia; chronic intravascular hemolysis causes hemoglobinuria and hemosiderinuria at an acid pH at night; PNH noted for low leukocyte alkaline phosphatase (LAP) score; Ham’s and sugar water tests used in diagnosis; increased incidence of acute leukemia.

Answer 27

Paroxysmal nocturnal hemoglobinuria (PNH)

Question 28

traditional method of diagnosing PNH

Answer 28

Ham’s and sugar water tests

Question 29

Standard method of diagnosing PNH

Answer 29

flow cytometry